LAUSR

The energy-efficient purification of methane from C2-hydrocarbons is of great significance for the upgrading of natural gas. So does the capture of carbon dioxide for remission of greenhouse effect. It is well established that some functional sites, such as open metals sites, Lewis basic nitrogen sites and fluorine groups, have shown significantly enhanced affinity toward more polarizable molecules. Thus, a water-stable Eu3+-based fcu-metal-organic framework (MOF) (compound 1) with amino functional groups has been successfully constructed through a reticular chemistry approach. As a result, the activated compound 1 exhibits moderately high uptakes of C2-hydrocarbons, but a less obvious adsorption of CH4 at the same conditions. Among them, the adsorption capacity of C2H2 is up to 143.6 cm3 cm−3 and a relatively high selectivity of C2H2/CH4 (107.7) is obtained at near room temperature. Moreover, compound 1 is also validated as an exceptional adsorbent for CO2 capture, with the fairly high capacity of CO2 (92.6 cm3 cm−3) and CO2/N2 selectivity (151.7) at ambient conditions. The excellent performance of compound 1 is mainly driven by the exposed amino functional groups within the contracted pores. Such effect thus leads to the achievement of dual-functional platform for methane purification and carbon dioxide capture. Furthermore, compound 1 features a satisfactory water stability, which is confirmed by the powder X-ray diffraction (PXRD) analysis and the retest of porosity after being soaked in water.摘要甲烷的高效净化对天然气的升级改造具有重要意义. 有效捕获二氧化碳对缓解温室效应同样具有重要的科研价值. 众所周知,在材料内部引入一些功能位点, 如开放金属位点、路易斯碱氮位点、氟基团, 可以显著提高材料对易极化分子的亲和力. 本文中,我们成功地构建了一种具有水稳性且携带氨基功能基团的铕基金属有机框架材料. 活化后的样品表现出较强的C2气体吸附, 但对甲烷的吸附不明显. 其中, 在近室温条件下, 样品对乙炔的吸附量可达143.6 cm3 cm−3, 并且可获得较高的乙炔/甲烷选择性分离系数(107.7). 此外, 该材料还被证实是一种优异的二氧化碳捕获吸附剂.在环境条件下, 具有较高的二氧化碳吸附量(92.6 cm3 cm−3)和二氧化碳/氮气选择性分离系数(151.7). 上述优异的小分子吸附分离性能主要由收缩孔笼内大量裸露的氨基官能团驱动所致. 这种独特的效应使该材料呈现优异的甲烷净化和二氧化碳捕获等多功能属性. 此外, 进一步PXRD分析与水中浸泡后孔隙率的重新测试证实,该材料具有令人满意的水稳定性.